Effects of feeding Candida ethanolica GXU01 on growth, immunity and intestinal flora of tilapia

To explore the probiotic potential of Candida ethanolica GXU01 in tilapia culture and to find ecological and friendly feeding bacteria for tilapia sustainable cultivation, we used C. ethanolica GXU01 as feed-additive to feed tilapia. Then we determined the growth performance, intestinal digestive enzymes, serum non-specific immune indexes and intestinal microbial community structure, and challenged the tilapia with Streptococcus agalactiae, so as to comprehensively evaluate the effects of C. ethanolica GXU01 on the growth and immunity of tilapia. The results show that the growth performance, digestive enzyme activity, serum lysozyme activity and complement C3 content of tilapia could be significantly improved by feeding C. ethanolica GXU01 (P<0.05). The abundance of Fusobacteria, Cetobacterium and Akkermansia in the intestinal tract of tilapia increased significantly and those of Cyanobacteria decreased significantly after feed of C. ethanolica GXU01. In the challenge test, the survival rate of tilapia fed with diet containing C. ethanolica GXU01 increased by 26.66%. The study shows that C. ethanolica GXU01 promotes the intestinal digestive ability and immune resistance of tilapia.